Most game engines today orient their feature set towards the creation of 3D games rather than 2D in a general sense. This often, ironically, makes 3D tasks and workflows simpler than 2D ones, at least to pick up and get started with initially. In this chapter, we'll explore a variety of 2D issues with some provisos. Since the release of Unity 4.3, a wide range of 2D features have been added to the editor: initially, a native sprite system and then, a new GUI system. While these are both useful in their respective ways, the main focus of this chapter will not be on these features specifically. The first reason is that a lot of tutorials already explain them in considerable detail, but the second and most important reason is that even with the added 2D features, there are still more fundamental questions that arise about working in 2D, in a looser sense. These include questions such as how to manipulate geometry such as the vertices and edges...